Hybrid Force-Motion Control for One-Legged Robot in Operational Space

This paper presents a dynamic locomotion generation for a one-legged floating-base robot. Reference synthesis is performed by planning both swing motion of the foot and contact forces acting from the ground. A fifth-order polynomial is employed as the position reference to reduce the impact forces and ensure a steady transition between the swing and stance phases. Contact force references are designed utilizing the laws of momentum conservation and impulse. A hybrid force-motion control framework is created in the operational space for tracking generated references. Gait phase transition is proposed to assist the transition between the force and motion controller. A full-dynamics simulation environment is utilized to test the proposed control framework. Results supported the competence of the proposed control framework for the floating-base one-legged robot.